package w1;

import java.sql.*;
import java.util.Scanner;


public class w1 {
    public static void main(String[] args) throws SQLException{
        //修改用户名和密码
        /**
         * 1.注册驱动
         * 2.获取链接
         * 3.创建表结构对象
         * 4.执行SQL语句
         * 5.操作返回结果
         * 6.关闭链接
         */
        Statement stmt = null;
        ResultSet rs = null;
        Connection conn = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            String url = "jdbc:mysql://localhost:3306/jdbc?serverTimezone=GMT%2b8&useSSL=false";
            String username = "root";
            String password = "112699";
            conn = DriverManager.getConnection(url, username, password);
//            stmt = conn.createStatement();
            /**
             * 静态sql语句用Statment
             * 动态sql语句用PreparedStatement
             */
            Scanner sc = new Scanner(System.in);
            System.out.println("请输入你的旧帐号名:");
            String n1 = sc.next();
            System.out.println("请输入你的旧密码");
            String p1 = sc.next();
            System.out.println("请输入你的新账号名：");
            String n2 = sc.next();
            System.out.println("请输入你的新密码：");
            String p2 = sc.next();

            String updateSQL = "update users set name= ?, password=? where name=? and password=?";
            PreparedStatement ps = conn.prepareStatement(updateSQL);
            ps.setString(1, n2);
            ps.setString(2, p2);
            ps.setString(3, n1);
            ps.setString(4, p1);
            int res = ps.executeUpdate();
            if (res > 0) {
                System.out.println("账号密码更新成功");
            } else {
                System.out.println("账号密码更新失败");
            }
        }catch (ClassNotFoundException e){
            e.printStackTrace();
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                rs = null;
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                stmt = null;
            }
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                conn = null;
            }
        }
    }
}
